Honda CRF250R 2018 Owner's Manual page 60

Cooling System Inspection
1. Check the cooling system for leaks (see an
official Honda Service Manual for
troubleshooting of leaks).
2. Check the radiator hoses (1) for cracks,
deterioration, and radiator hose clamps for
looseness.
3. Check the radiator mount for looseness.
4. Make sure the overflow hose (2) is connected
and not clogged.
5. Check the radiator fins (3) for clogging.
(3)
(1)
(1) radiator hoses (3) radiator fins
(2) overflow hose
6. Check the bleed hole (4) below the water pump
cover (5) for leakage. Clean away any clogged
dirt or sand, if necessary. Check the bleed hole
of the water pump for signs of seal leakage. If
water leaks through the bleed hole, replace the
mechanical seal. If oil leaks through the bleed
hole, replace the oil seal. Make sure that there
is no continuous coolant leakage from the
bleed hole while operating the engine.
A small amount of coolant weeping from the
bleed hole is normal. See an official Honda
Service Manual or consult your dealer for
replacing the mechanical seal or oil seal.
Both seals should be replaced at the same time.
(2)
(4)
(3)
(4) bleed hole
(5) water pump cover
7. Check the radiator air passages for clogging or
damage.
Straighten bent fins (6), and remove insects,
mud or other obstructions with compressed air
(1)
or low water pressure.
Replace the radiator if the air flow is restricted
over more than 20% of the radiating surface.
(6)
(6) fins
Radiator should be replaced by your dealer, unless
you have the proper tools and service data and are
mechanically qualified. Refer to an official Honda
Service Manual (page 166).
Coolant Replacement
Refer to Important Safety Precautions on page 23.
Coolant should be replaced by your dealer, unless
you have the proper tools and service data and are
mechanically qualified. Refer to an official Honda
Service Manual (page 166).
(5)
WARNING
Removing the radiator cap while the
engine is hot can cause the coolant to
spray out, seriously scalding you.
Always let the engine and radiator cool
down before removing the radiator cap.
To properly dispose of drained coolant, refer to
You & the Environment on page 146.
NOTICE
Improper disposal of drained fluids is harmful to
the environment.
Coolant
55
Servicing Your Honda